The present invention relates generally to apparatus and methods for cooking foods on an automated basis utilizing a conveyor for transporting foods through a heated cooking area. In particular, the present invention relates to such an apparatus and method specifically adapted for broiling whole chickens and other meats.
Over recent years, consumers have become increasingly concerned with fat and cholesterol content of many common and popular foods, particularly meats. As a result, the rate of consumption of leaner types of meats, particularly chicken and other poultry, has been progressively increasing. At the same time, the methods by which meat and other foods are prepared is now viewed as being of equal importance, oil-based frying of foods being disfavored because it substantially increases the fat content of prepared foods while broiling of foods has become increasingly popular since this preparation method involves no addition of fat to the food.
Disadvantageously, however, the increased popularity of broiling as a food preparation method poses several problems for restaurant owners and others involved in commercial and large-scale preparation of foods. One of the most common commercial food broiling systems utilizes a grill suspended over a heat-generating source, typically a gas-fueled burner. During the cooking of virtually any meat on such a broiling apparatus, fat rendered from the meat falls onto the burner producing a considerable amount of smoke, fire and fumes, all of which must be exhausted from the cooking area. In order to do so in many restaurants and other large-scale food preparation operations, it is necessary to maintain high rates of air exhaust from the cooking area, generally through an exhaust flue and filtering arrangement. While a sufficiently high rate of air exhaust is sufficient in most cases to maintain the cooking and serving areas of restaurants and like establishments substantially free of smoke and fumes, the operators of such establishments incur substantially increased equipment and operational expenses for both the exhaust system and for air conditioning and heating the establishment. Further, various Federal, State and/or local laws and regulations prohibit the direct release of the exhausted effluent of the cooking process into the ambient atmosphere. Accordingly, an air filtering arrangement of a capacity suitable to handle air at the prevailing rate of exhaust must be utilized, additionally increasing the cost of operation. Finally, broiling apparatus of this basic type generally require an operator with a reasonably high level of skill and experience to attend the meat being cooked on the apparatus to insure sufficient cooking without overcooking and burning of the meat.
Various types of automated cooking apparatus have been proposed wherein meat is transported by a continuous conveyor system between vertically-oriented opposed facing burners or other cooking elements to reduce the generation of smoke and fumes while at the same time automating the cooking process. Representative examples of such apparatus are disclosed in U.S. Pat. Nos. 2,718,188 to Read et. al.; 3,646,879 to Palmason et. al.; 4,366,182 to Kohler et. al.; and 4,753,216 to Nolte. Of these apparatus, only the Kohler et. al. patent contemplates use of such an apparatus for cooking whole chickens or other relatively large irregularly-shaped meat items, the apparatus of the other patents being particularly designed and intended for broiling steaks, chops, hamburgers and the like.
One of the most important criteria for the commercial acceptability of any such apparatus is that the meat item must be uniformlly cooked over its entire mass. Since many common meat items are typically of a non-uniform thickness and have a non-uniform distribution of fat (with the possible exception of hamburger patties), this criteria is difficult to reliably achieve on a repeatable regular basis in a commercial setting utilizing an apparatus of the type of the above-identified patents wherein substantially the same amount of cooking heat energy is applied by the opposed burners to all exposed surfaces of the meat item without regard to any inherent irregularities in shape, thickness and fat content of the meat.
This problem would be particularly acute in the broiling of whole chickens as contemplated in the Kohler patent due to the irregular shape of chickens and the irregular distribution of fat, which is concentrated under the skin of the chicken in the region of the thighs and back. In this respect, conventional grill-type broiling apparatus have a notable advantage over conveyorized apparatus of the type of the above-identified patents in that a skilled attendant can regulate the uniformity of cooking of meat items by continuously turning the meat items and changing their position on the grill.
Another consideration in the design of automated conveyorized cooking apparatus is the need to provide the apparatus with the capability of cooking food products to a uniform degree without regard to the rate or frequency with which food products are delivered by the conveyor arrangement into the cooking apparatus, which necessarily will vary depending upon fluctuations in customer demand. Assuming the preferred condition that the actual cooking time for each food product should be constant whether during peak or low customer periods, it is important that the air temperature within the cooking apparatus be at least generally constant, and preferably relatively low in relation to the heat-generating burners or elements. As will be understood, as the air temperature within the cooking apparatus increases, the heated air contributes to a greater extent in the cooking process. Thus, under conditions of relatively high internal air temperature within the cooking apparatus, as the frequency with which food products are conveyed through the cooking apparatus increases, the internal air temperature will be progressively decreased resulting in a progressive reduction in the degree to which each food item is cooked.